I'm extremely new to using Makefiles and autoconf. I'm using the Camellia image library and trying to statically link my code against their libraries. When I run "make" on the Camellia image library, I get libCamellia.a, .so, .la, and .so.0.0.0 files inside my /usr/local/lib directory. This is the command I use to compile my code with their libraries:
gcc -L/usr/local/lib -lCamellia -o myprogram myprogram.c
This works fine, but when I try to statically link, this is what I get:
gcc -static -L/usr/local/lib -lCamellia -o myprogram myprogram.c /tmp/cck0pw70.o: In function `main': myprogram.c:(.text+0x23): undefined reference to `camLoadPGM' myprogram.c:(.text+0x55): undefined reference to `camAllocateImage' myprogram.c:(.text+0x97): undefined reference to `camZoom2x' myprogram.c:(.text+0x104): undefined reference to `camSavePGM' collect2: ld returned 1 exit status
I want to statically link because I'm trying to modify the Camellia source code and I want to compare my version against theirs. So after some googling, I tried adding AM_DISABLE_SHARED into the configure.in file. But after running ./configure, I still get the exact same Makefile. After I "make install", I still get the same results above.
What is an easy way to get two versions of my code, one with the original Camellia source code compiled and one with my modified version? I think static libraries should work. There is an easy way to get static libraries working or are there other simple solutions to my problem? I just don't want to re-"make" and re-"make install" everytime I want to compare my version against the original.Answer1:
Did you re-run
autoconf after adding
AM_DISABLE_SHARED and before configure, make, make install? You also can just use
configure --disable-dynamic to stop it building the shared libraries. Make sure you delete any previously installed ones -
make uninstall should do that. I can't see anything else obviously wrong. Try being explicit:
gcc -static -o myprogram myprogram.c /usr/local/lib/libCamellia.a
or break it down into two steps and check the symbols in
myprogram.o are what you expect with
I am not skillful with autoconf and I don't know why your attempt to link statically fails, but if linking dynamically works I think using shared libraries would actually solve your problem a little better.
Just make two shared libraries, one with the original Camellia code and one with your modified version. Put them in two different directories, and when you run
myprogram you can choose between them either by switching LD_LIBRARY_PATH (or whatever you're using to find libraries) or by keeping a symbolic link in
/usr/local/lib and switching it between libraries. The advantage of this over static libraries (apart from the fact that this works) is that you can tinker with your modified code, rebuild the shared library and run without having to rebuild
myprogram (as long as you don't modify the signatures).
P.S. An experiment: try removing the shared libraries from
/usr/local/lib and rebuilding without the
-static flag, just as if you were using the shared libraries. In theory this should cause gcc to use the static libraries instead. The results may give a clue to why the static link is failing.